The present invention concerns an electromagnetic actuator device as well as the use of such an electromagnetic actuator device as a positioning device for a combustion engine unit.
Electromagnetic positioning devices have been of known prior art for a long time as actuators, in particular for a camshaft positioning unit, or a similar unit of a combustion engine. Thus, for example, the applicant's German patent 102 40 774 shows such a technology, in which an armature unit having a permanent magnetic agent has at its end a tappet or tappet section designed to interact with a positioning partner (for example, a positioning groove of a camshaft adjustment system), and can be moved relative to a static yoke or core unit as a reaction to an energisation of a (stationary) coil unit. In concrete terms the reaction to the energisation in such devices is generated as a repulsive electromagnetic field, which releases the armature unit from an initial position on the yoke unit and drives it in the direction towards an engagement position with the positioning partner.
Such devices of presupposed known art are not only electromagnetic and optimised with regard to their dynamic behaviour (force and velocity development); these devices are also suitable in a particularly beneficial manner for large-scale production.
However, such an approach, as structurally determined, also has disadvantages, which in particular limit the flexibility of the adaptation of this technology to various conditions of deployment. Thus the technology presupposed as of known art, in the first instance the permanent magnetic agents (typically implemented in the form of a permanent magnetic disk or similar) to be provided on the armature and thus movable, requires protection of this armature unit from impacts, shocks or similar, so as to protect the typically brittle permanent magnetic material, and thus to ensure as long a service life as possible. DE 102 40 774, cited as prior art, solves this problem in that the armature-side permanent magnetic disk is bounded on both flat faces by (flux-conducting) metal disks and is additionally encased, so that even severe positive and negative accelerations onto the armature unit do not cause any damage to the permanent magnetic module. At the same time geometric limits are determined by such approaches, which, for example, define typical maximum sizes for such feasibility in the radial or axial directions.
Thus there is a fundamental disadvantage of the technology of known art, namely that for purposes of increasing the forces the armature-side permanent magnetic agents must also be increased in size correspondingly, with the effect that the masses to be moved (by the armature) increase accordingly (in addition to the above-mentioned measures for the mechanical protection of the permanent magnetic material).